1. Field of the Invention
The present invention relates to keyboard technology and more particularly, to a keyboard lifting structure, which comprises a plurality of driving devices disposed in between a base and a cover frame beneath respective key caps, and a lifting mechanism disposed between the base and the cover frame, and adapted for moving said cover frame vertically relative to said base and simultaneously causing the driving devices to move the respective key caps in or out of respective openings in the cover frame.
2. Description of the Related Art
With fast development of the modern technology, many different kinds of electrical and electronic products have been created and widely used in our daily life, bringing comfort and convenience to people and improving the standard of living of the people. The jobs of word processing, photos and graphics editing, presentations, e-mail, Internet linking, and etc. are quite common in our everyday lives, making the application of computer products become more popular. In various electronic works through a computer system, one must input data through a keyboard, so that the host of the computer system can start processing according to the inputted data. Therefore, a computer keyboard has become an essential tool for the computer jobs. It is now the market trends to design computers and peripheral apparatuses having light, thin, short and small characteristics and enhanced functions, the overall thickness of a computer, more particularly, notebook computer, must be greatly reduced. In consequence, the thickness of computer display screens and keyboards must also be greatly reduced.
For the advantages of being easy to carry and to operate and having no time, place or geographic restrictions, notebook computer has been widely used by people. Sometimes, keycaps might be inadvertently depressed to activate an inadvertent keystroke. In order to prevent this problem, a notebook computer can be equipped with an anti-touch security device that is operable to lift the keyboard cover frame to the elevation around the topmost edges of the key caps to stop the key caps from downward displacement. When the user wishes to use the notebook computer again, the user can operate the anti-touch security device to lower the keyboard cover frame to its former position, allowing clicking of the key caps to input electronic signals. However, the cover frame lifting distance must be larger than the thickness of the key caps so that the key caps can be completely received in respective openings in the keyboard cover frame when the keyboard cover frame is lifted. To achieve this design requirement, the keyboard cover frame must be lifted upwardly from the keyboard base to a distance about 2.0 mm where the keyboard base is kept approximately in a flush manner relative to the topmost edges of the key caps. However, this large lifting distance prohibits reduction of the overall height of the keyboard and causes an increase in the height of the keyboard, making the notebook computer unable to meet the design concept of being light, thin, short and small. Further, this anti-touch security device uses a lifting mechanism to lift the keyboard cover frame to the elevation in flush with the topmost edges of the key caps. Because the lifting mechanism simply acts upon a specific area of the bottom surface of the keyboard cover frame when lifting the keyboard cover frame, the rectangular keyboard cover frame may be not kept in balance, complicating the lifting mechanism lifting operation. An improvement in this regard is needed.